What is the half-life (in $\text{min}$) of a radioactive substance if $75\%$ of a given amount of the substance disintegrates in $30 \, \text{min}$?

$A$ certain nuclide has a half-life of $25 \ min$. If one starts with $100 \ g$ of it,how much of it will remain at the end of $100 \ min$?

What type of reaction order is followed by radioactive processes?

The half-life of a radioactive element is $6 \ months$. The time taken to reduce its original concentration to its $1/16$ value is ....... $years$.

What is the half-life period of a nucleus in $days$ if at the end of $4.2$ $days$,$N = 0.798 \ N_0$?

$A$ radioactive sample is emitting $64$ times more radiation than the non-hazardous limit. If its half-life is $2 \ hr$,after what time will it become non-hazardous? $(hr)$